将一个切片/数组传递给另一个结构体。

huangapple
go评论112阅读模式
英文:

passing a slice/array to another struct

问题

我有以下对我有效的代码。

  1. params := &cloudformation.CreateStackInput{
  2. 	StackName:   aws.String(d.MachineName),
  3. 	TemplateURL: aws.String(d.CloudFormationURL),
  4. 	Parameters: []*cloudformation.Parameter{
  5. 		{
  6. 			ParameterKey:   aws.String("KeyName"),
  7. 			ParameterValue: aws.String(d.KeyPairName),
  8. 		},
  9. 	},
  10. }

我想将参数的创建外部化，所以我创建了以下方法。

  1. func (d *Driver) createParams() []cloudformation.Parameter {
  2. 	val := "KeyName=Foo|KeyName2=bar"
  3. 	s := strings.Split(val, "|")
  4. 	a := []cloudformation.Parameter{}
  6. 	for _, element := range s {
  7. 		pairs := strings.Split(element, "=")
  8. 		key := pairs[0]
  9. 		value := pairs[1]
  10. 		par := cloudformation.Parameter{
  11. 			ParameterKey:   aws.String(key),
  12. 			ParameterValue: aws.String(value),
  13. 		}
  14. 		a = append(a, par)
  15. 	}
  17. 	return a
  18. }

我的问题是如何将createParams的输出传递给CreateStackInput的Parameters字段？

  1. params := &cloudformation.CreateStackInput{
  2. 	StackName:   aws.String(d.MachineName),
  3. 	TemplateURL: aws.String(d.CloudFormationURL),
  4. 	Parameters:  d.createParams(),
  5. }

上述代码会产生以下错误：

  1. cannot use d.createParams() (type []cloudformation.Parameter) as type []*cloudformation.Parameter in field value
英文:

I have the following code that works for me.

  1. params := &cloudformation.CreateStackInput{
  2. 	StackName:   aws.String(d.MachineName),
  3. 	TemplateURL: aws.String(d.CloudFormationURL),
  4. 	Parameters: []*cloudformation.Parameter{
  5. 		{
  6. 			ParameterKey:   aws.String("KeyName"),
  7. 			ParameterValue: aws.String(d.KeyPairName),
  8. 		},
  9. 	},
  10. }

I would like to externalize the creation of the Parameters, so I have created the following method.

  1. func (d *Driver) createParams() []cloudformation.Parameter {
  3. val := "KeyName=Foo|KeyName2=bar"
  5. s := strings.Split(val, "|")
  7. a := []cloudformation.Parameter{}
  9. for _, element := range s {
  11. 	pairs := strings.Split(element, "=")
  13. 	key := pairs[0]
  14. 	value := pairs[1]
  16. 	par := cloudformation.Parameter{
  17. 		ParameterKey:   aws.String(key),
  18. 		ParameterValue: aws.String(value),
  19. 	}
  21. 	a = append(a, par)
  23. }
  25. return a

}

My issue is how to I pass the output of createParams to the Parameters from CreateStackInput?

  1. params := &cloudformation.CreateStackInput{
  2. 	StackName:   aws.String(d.MachineName),
  3. 	TemplateURL: aws.String(d.CloudFormationURL),
  4. 	Parameters:  d.createParam(),
  5. }

The above yields

  1. cannot use d.createParam() (type []cloudformation.Parameter) as type []*cloudformation.Parameter in field value

答案1

得分: 0

指针类型与它们指向的解引用类型不兼容，错误提示告诉你这一点，因为你试图将[]*cloudformation.Parameter设置为[]cloudformation.Parameter。将createParams的返回类型更改为[]*cloudformation.Parameter，并设置par := &cloudformation.Parameter。

  1. func (d *Driver) createParams() []*cloudformation.Parameter {
  2.   val := "KeyName=Foo|KeyName2=bar"
  3.   s := strings.Split(val, "|")
  4.   a := []*cloudformation.Parameter{} // a 应该是指针的切片
  5.   for _, element := range s {
  6.       pairs := strings.Split(element, "=")
  7.       key := pairs[0]
  8.       value := pairs[1]
  9.       par := &cloudformation.Parameter{ // & 将 par 转换为参数的指针
  10.           ParameterKey:   aws.String(key),
  11.           ParameterValue: aws.String(value),
  12.       }
  13.       a = append(a, par)
  14.     }
  15.   return a
  16. }
英文:

Pointer types are not compatible with the dereferenced types they point to, the error is telling you this very thing as you are trying to set a []*cloudformation.Parameter to a []cloudformation.Parameter. Change the return type of createParams to []*cloudformation.Parameter and set par := &cloudformation.Parameter.

  1. func (d *Driver) createParams() []*cloudformation.Parameter {
  2.   val := "KeyName=Foo|KeyName2=bar"
  3.   s := strings.Split(val, "|")
  4.   a := []*cloudformation.Parameter{} //a should be a slice of pointers
  5.   for _, element := range s {
  6.       pairs := strings.Split(element, "=")
  7.       key := pairs[0]
  8.       value := pairs[1]
  9.       par := &cloudformation.Parameter{ //& turns par into a pointer to the parameter
  10.           ParameterKey:   aws.String(key),
  11.           ParameterValue: aws.String(value),
  12.       }
  13.       a = append(a, par)
  14.     }
  15.   return a
  16.   }

huangapple
  • 本文由 发表于 2015年11月19日 04:18:14
  • 转载请务必保留本文链接：https://go.coder-hub.com/33789572.html
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